ATMEGA8535-16PJ - 8KB AVR MCU 16MHz 40-PDIP | Microchip
MPN: ATMEGA8535-16PJ β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.42 | $5.42 |
| 10 | $4.88 | $48.80 |
| 100 | $4.25 | $425.00 |
| 500 | $3.82 | $1,910.00 |
| 1,000 | $3.4 | $3,400.00 |
ATMEGA8535-16PJ Overview
An AVR ATmega microcontroller is an 8-bit RISC-based MCU built on the Harvard architecture, in which program memory and data memory use separate buses so most instructions execute in a single clock cycle. Within the electronics hierarchy it sits under microcontroller -> embedded processor -> integrated circuit, and it belongs to the wider family of AVR flash MCUs that Microchip inherited from Atmel. These MCUs are favored for their simple toolchain, in-system programmability, and strong single-cycle I/O control.
Key features include 130 powerful instructions with mostly single-cycle execution, 32 general-purpose I/O lines organized in four 8-bit ports (PORTA through PORTD), and the 8-channel 10-bit successive-approximation ADC on PORTA for direct analog sensor connection. Communication is handled by an SPI interface and a full UART/USART, enabling connectivity to displays, memories, and other MCUs. Internal and external interrupt sources, a 16-bit Timer/Counter1 with PWM outputs, two 8-bit timers, and an on-chip brown-out detector round out the peripheral set.
Technically, the fully static design allows the clock to be stopped and restarted without loss of state, and self-programming Flash supports field firmware updates through boot-loader code. Power management modes, including idle and power-down, let battery-sensitive designs average down the 5 V rail consumption. The 40-pin PDIP package has 0.1 inch pin pitch, which suits sockets, breadboards, and hand or wave soldering in repairable industrial equipment.
Typical applications include legacy industrial control boards, motor and actuator control with PWM, instrumentation and data loggers using the 10-bit ADC, and educational or hobby systems where DIP packaging allows easy replacement and rework. It is also a direct fit for maintaining equipment originally designed around the Atmel AT90S8535.
When designing with the ATMEGA8535-16PJ, remember the 4.5 V to 5.5 V operating window: it cannot run at 3.3 V. Decouple VCC and AVCC separately and keep analog traces away from the USART lines to preserve ADC accuracy.
This page synthesizes verified distributor specifications, drop-in replacement options, pinout data, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for ATMEGA8535-16PJ β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ATMEGA8535-16PJ (same form factor and footprint) β differing in Communication Interfaces, Package, Core Architecture, Operating Temperature, Throughput.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
ATMEGA8535-16PU
β Drop-Inβ In Stock
$2.05 / Unit
View Datasheet βATMEGA8535-16PI
β Drop-Inπ Reference alternative (not in catalog)
AT90S8535-16PJ
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
ATMEGA8515-16JI
β Drop-Inβ In Stock
$5.44 / Unit
View Datasheet βATMEGA8515-16JC
β Drop-Inβ In Stock
$2.85 / Unit
View Datasheet βATMEGA8535-16PJ Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit AVR RISC |
| Flash Program Memory | 8 KB (4K x 16) |
| SRAM | 544 bytes |
| EEPROM | 512 bytes |
| Maximum Clock Frequency | 16 MHz |
| Throughput | Up to 16 MIPS at 16 MHz |
| Instructions | 130 instructions, most single-cycle |
| Supply Voltage | 4.5 V to 5.5 V |
| ADC | 8-channel 10-bit |
| GPIO Count | 32 I/O lines |
| Communication Interfaces | SPI, UART/USART, I2C |
| Timers | Two 8-bit, one 16-bit with PWM |
| Package | 40-PDIP (0.600 inch, through-hole) |
| Mounting Type | Through Hole |
| Operating Temperature | 0C to +70C (P grade, commercial) |
| Programmability | Self-programming Flash, ISP |
| RoHS Status | Compliant |
ATMEGA8535-16PJ Pin Configuration
| Pin 1 | PB0 (XCK/T0) β Port B bit 0 / USART external clock / Timer0 external clock |
| Pin 2 | PB1 (T1) β Port B bit 1 / Timer1 external clock |
| Pin 3 | PB2 (AIN0/INT2) β Port B bit 2 / analog comparator positive input / external interrupt 2 |
| Pin 4 | PB3 (AIN1/OC0) β Port B bit 3 / analog comparator negative input / Timer0 output compare |
| Pin 5 | PB4 (SS) β Port B bit 4 / SPI slave select |
| Pin 6 | PB5 (MOSI) β Port B bit 5 / SPI master output / ISP data in |
| Pin 7 | PB6 (MISO) β Port B bit 6 / SPI master input / ISP data out |
| Pin 8 | PB7 (SCK) β Port B bit 7 / SPI clock / ISP serial clock |
| Pin 9 | RESET β Active-low reset input, also ISP programming strobe |
| Pin 10 | VCC β Digital supply voltage, 4.5 V to 5.5 V |
| Pin 11 | GND β Ground |
| Pin 12 | XTAL2 β Inverting oscillator amplifier output |
| Pin 13 | XTAL1 β Inverting oscillator amplifier input / external clock input |
| Pin 14 | PD0 (RXD) β Port D bit 0 / USART receive data |
| Pin 15 | PD1 (TXD) β Port D bit 1 / USART transmit data |
| Pin 16 | PD2 (INT0) β Port D bit 2 / external interrupt 0 |
| Pin 17 | PD3 (INT1) β Port D bit 3 / external interrupt 1 |
| Pin 18 | PD4 (OC1B) β Port D bit 4 / Timer1 output compare B (PWM) |
| Pin 19 | PD5 (OC1A) β Port D bit 5 / Timer1 output compare A (PWM) |
| Pin 20 | PD6 (ICP1) β Port D bit 6 / Timer1 input capture |
| Pin 21 | PD7 (OC2) β Port D bit 7 / Timer2 output compare (PWM) |
| Pin 22 | PC0 β Port C bit 0, general-purpose I/O |
| Pin 23 | PC1 β Port C bit 1, general-purpose I/O |
| Pin 24 | PC2 β Port C bit 2, general-purpose I/O |
| Pin 25 | PC3 β Port C bit 3, general-purpose I/O |
| Pin 26 | PC4 β Port C bit 4, general-purpose I/O |
| Pin 27 | PC5 β Port C bit 5, general-purpose I/O |
| Pin 28 | PC6 β Port C bit 6, general-purpose I/O |
| Pin 29 | PC7 β Port C bit 7, general-purpose I/O |
| Pin 30 | AVCC β ADC and Port A supply voltage, connect to VCC via low-pass filter |
| Pin 31 | GND β Ground |
| Pin 32 | AREF β ADC reference voltage, decouple to GND when using internal reference |
| Pin 33 | PA0 (ADC0) β Port A bit 0 / ADC channel 0 |
| Pin 34 | PA1 (ADC1) β Port A bit 1 / ADC channel 1 |
| Pin 35 | PA2 (ADC2) β Port A bit 2 / ADC channel 2 |
| Pin 36 | PA3 (ADC3) β Port A bit 3 / ADC channel 3 |
| Pin 37 | PA4 (ADC4) β Port A bit 4 / ADC channel 4 |
| Pin 38 | PA5 (ADC5) β Port A bit 5 / ADC channel 5 |
| Pin 39 | PA6 (ADC6) β Port A bit 6 / ADC channel 6 |
| Pin 40 | PA7 (ADC7) β Port A bit 7 / ADC channel 7 |
Typical Applications
ATMEGA8535-16PJ is suitable for 6 applications: Industrial Control and Legacy Board Maintenance, Analog Sensor Data Loggers, PWM Motor and Actuator Control, Education and Prototyping on Breadboards, Embedded Communication Nodes, Instrumentation Front Panels and Displays.
Industrial Control and Legacy Board Maintenance
The ATMEGA8535-16PJ fits industrial control retrofits because its 5 V logic, 32 GPIO lines, and through-hole 40-pin PDIP package match the boards installed in PLC I/O racks, relay controllers, and machine sensors built in the late 1990s and 2000s. The self-programming 8 KB Flash lets technicians update firmware in the field through a USART boot loader without desoldering the IC, and the DIP footprint plugs into standard sockets for tool-free replacement. Its fully static core tolerates slow or noisy clocks during commissioning. For equipment originally designed around the AT90S8535 or ATmega8535, this part preserves firmware compatibility and eliminates PCB rework, which is the dominant cost driver in legacy board repair.
Recommended
Analog Sensor Data Loggers
Data-logging instruments benefit directly from the ATMEGA8535-16PJ's 8-channel 10-bit successive-approximation ADC on PORTA, which digitizes up to eight sensors such as thermistors, pressure transducers, and potentiometer position feedback without any external converter IC. The 512 bytes of EEPROM retain calibration constants and logging checkpoints through power loss, while the USART streams readings to a host or modem at standard baud rates. Timer/Counter1's input capture can timestamp external pulse events with 16-bit resolution. AVCC must be tied to a clean 5 V rail and AREF decoupled to hold ADC linearity; in exchange, a single 40-pin PDIP replaces what would otherwise require an MCU plus a separate ADC and serial EEPROM.
Recommended
PWM Motor and Actuator Control
The 16-bit Timer/Counter1 generates PWM on OC1A (PD5) and OC1B (PD4), enabling closed-loop DC and stepper motor control directly from the ATMEGA8535-16PJ. Input capture on PD6 reads encoder or hall-sensor feedback with 16-bit precision, and external interrupts INT0/INT1 on PD2/PD3 handle limit-switch and fault inputs with immediate response. At 16 MHz, PWM resolution reaches 8-bit at approximately 62.5 kHz or 10-bit at roughly 15.6 kHz, covering both quiet fan control and torque control loops. The 5 V I/O drives classic H-bridge and MOSFET gate-driver families without level shifting, simplifying the power stage on legacy industrial 24 V machines.
Recommended
Education and Prototyping on Breadboards
With its 0.1-inch pin pitch, 40-pin PDIP package, the ATMEGA8535-16PJ inserts directly into solderless breadboards and ZIF sockets, making it a mainstay of microcontroller courses and prototype builds. Students program it through the SPI ISP header (PB5-PB7 plus RESET) with free AVRDude-based toolchains and no surface-mount rework equipment. The 130-instruction AVR RISC set, mostly single-cycle, teaches assembly and C fundamentals with predictable timing, while the ADC, timers, USART, and SPI provide complete peripheral coverage in one part. Because the DIP is socketed, learners can swap chips, recover from latch-up damage, and reuse boards indefinitely - a practical advantage no QFN or TQFP part offers in a teaching lab.
Recommended
Embedded Communication Nodes
The ATMEGA8535-16PJ serves as a low-cost communication node using its hardware SPI and full-duplex USART. The USART connects to RS-485 transceivers or modems for fieldbus endpoints, while SPI links to external EEPROM, real-time clocks, and display controllers, allowing an 8 KB Flash part to supervise a complete node. Timer0 provides the USART baud-rate clock, and the multi-processor communication mode supports addressed RS-485 networks. At 16 MHz the core sustains 115200-baud streaming with headroom for protocol layers such as Modus-style polling. Because the part operates from a single 5 V rail, it interfaces directly with legacy RS-232/RS-485 transceiver families common in installed industrial networks.
Recommended
Instrumentation Front Panels and Displays
Bench instruments, counters, and metering products use the ATMEGA8535-16PJ to drive multiplexed 7-segment displays and read keypads with ample GPIO. Eight PORTA/PORTC pins can sink or source segment lines while the remaining ports scan keys and control LED indicators, all with single-cycle I/O for glitch-free multiplexing. The 10-bit ADC digitizes a measured input (current, voltage via divider, or potentiometer setting) for display, and the USART sends readings to a PC for logging. The 5 V DIP device suits the through-hole PCBs typical of instrument front panels, where hand solderability and socket serviceability matter more than footprint size, keeping repair cycles fast and inexpensive.
Recommended
Recommended Products Summary
Engineering reference data for ATMEGA8535-16PJ β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATMEGA8535-16PU | ATMEGA8535-16PI | AT90S8535-16PJ | ATMEGA8515-16JI |
|---|---|---|---|---|---|
| Package | 40-PDIP (through-hole) | 40-PDIP - same | 40-PDIP - same | 40-PDIP - same | 40-PDIP - same |
| Brand | Microchip Technology (Atmel) | Microchip Technology | Microchip Technology | Microchip Technology (Atmel) | Microchip Technology |
| Flash Memory | 8 KB (4K x 16), self-programming | 8 KB, self-programming | 8 KB, self-programming | 8 KB, OTP (not electrically erasable) | 8 KB, self-programming |
| SRAM | 544 bytes | 544 bytes | 544 bytes | 512 bytes | 512 bytes |
| ADC | 8-channel 10-bit | 8-channel 10-bit | 8-channel 10-bit | 8-channel 10-bit | None - digital only |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.0 V to 5.5 V | 4.5 V to 5.5 V |
| Maximum Clock / MIPS | 16 MHz / 16 MIPS | 16 MHz / 16 MIPS | 16 MHz / 16 MIPS | 16 MHz / 16 MIPS | 16 MHz / 16 MIPS |
| Operating Temperature | 0C to +70C (commercial) | 0C to +70C | -40C to +85C (industrial) | 0C to +70C | -40C to +85C (industrial) |
Key Differentiators
- Integrated 8-channel 10-bit ADC in a DIP-40 footprint (vs ATMEGA8515-16JI)
- Electrically erasable self-programming Flash (vs AT90S8535-16PJ)
- Commercial-temperature cost optimization (vs ATMEGA8535-16PI)
Design Notes
The -16PJ requires a 4.5 V to 5.5 V supply and cannot run at 3.3 V - do not substitute it into low-voltage designs. Decouple VCC (pin 10) with a 100 nF ceramic placed within 5 mm of the pin, and feed AVCC (pin 30) through an RC low-pass filter (e.g., 10 ohm / 100 nF) from VCC to keep ADC reference noise low. Enable the on-chip brown-out detector so EEPROM writes are blocked during supply dips; corrupted EEPROM is the most common field failure on legacy AVR designs. Estimated: at 16 MHz and 5 V, active current is roughly 15-25 mA, about 0.075-0.125 W dissipation - no heatsink needed.
Although the 40-pin PDIP is forgiving, layout still affects ADC accuracy: route the PORTA (ADC) traces away from the XTAL1/XTAL2 crystal lines and the USART TX/RX pairs to prevent digital coupling into analog readings. Decouple AREF (pin 32) with 100 nF to GND when using the internal reference, and do not load AREF with an external DC voltage unless the ADC is disabled. Use a crystal with appropriate load capacitors (typically 22 pF for common 16 MHz HC-49 crystals) on XTAL1/XTAL2, keeping the crystal tracks short and guarded by ground.
Do not confuse suffix codes when sourcing: -16PJ and -16PU are both commercial-temperature DIP parts differing in packaging processing, while -16PI adds the industrial -40C to +85C range; using a P/J part in an unheated outdoor enclosure violates the datasheet temperature rating. Also note the ATMEGA8515 is pin-compatible but has no ADC - swapping it into an ATmega8535 socket will read floating inputs on PORTA. Finally, RESET (pin 9) is active-low with an internal pull-up only on some config; add a 10 kohm external pull-up and a 100 nF cap to GND for reliable ISP programming.
Compliance Information
The -PJ suffix on Microchip/Atmel AVR parts denotes the lead-free, RoHS-compliant processed variant of the PDIP package, per distributor listings. REACH, halogen-free, and conflict-minerals status not stated in the provided web data.
